Browsing by Author "Myskiv, Teodozii"

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Analysis of the drive of electric vehicles with its different configurations
(Видавництво Львівської політехніки, 2023-02-28) Myskiv, Teodozii; Lviv Polytechnic National University
In the process of car development, its drive is continuously improved. The properties of different types of driving with an internal combustion engine (ICE) are well-studied [1]. ICE's bleak future has forced major automotive manufacturers to turn to electric mobility. The motor, integrated with final drive and differential, is compact and takes up little axle space, making it easier to assemble the drive into one axle or all-wheel drive. Electric vehicles have many advantages over vehicles with ICE: no emissions, high efficiency, quiet and smooth operation, braking energy recovery, simplified maintenance, etc. The functional and fundamental principles of electric vehicles and vehicles with ICE are similar, but there are some features. The characteristic of the electric motor (hereinafter referred to as the motor) is ideal for the drive – it has a large zone of constant maximum power, and the maximumtorque appears immediately during starting. The motor, integrated with final drive and differential, is compact and takes up little axle space, making it easier to assemble the drive into one axle or all-wheel drive. Possible drive designs without a differential with two motors and two final drives on the axle, or with low-speed motors without final drives. The heavy battery is placed in the floor, so the stability of the electric car is high. The maximum possible recovery of braking energy is added to all the positive properties of allwheel drive in the case of an electric car. To reduce the power consumption in the drive, two motors provide a drive mode with only one motor. Among electric vehicles with one-axle drive, front-wheel drive prevails due to using multienergetic front-wheel drive platforms, stable stability and handling performance and good traction properties in winter conditions. The advantage of rear-wheel drive is the ability to realize greater traction forces during acceleration or movement on the rise due to the dynamic redistribution of the load on the rear axle. However, during braking, due to the dynamic redistribution of the load on the front axle, the possibility of recuperation of braking energy decreases. For amore detailed analysis of the drive, typical electric vehicles are selected, the characteristics of their drive motors are given, traction characteristics are calculated and constructed in the traction force coordinates – speed of movement, the realized adhesion coefficients are determined, and appropriate conclusions have been drawn.
Analysis of vehicles drive with different characteristics of power supply
(Видавництво Львівської політехніки, 2022-02-22) Myskiv, Teodozii; Sorokivskyi, Oleg; Lviv Polytechnic National University
The characteristics of internal combustion engines (hereinafter referred to as ICE) have the following disadvantages: there is a gap between zero and minimum angular velocity, so it is impossible to move out of a state of rest; the dependence of torque on angular velocity is not ideal. They are corrected by the following converters: the first by a clutch or torque converter, and the second by a gearbox or variator. In addition, the ICE characteristics can be partially close themselves to ideal. Electric motors (here in after referred to as motors) of electric vehicles have an ideal characteristic that starts from scratch and has a large zone with a sustainable maximum power. The addition of the drive with the ICE motor in hybrid electric cars solves these problems. The different characteristics of ICE, motors and converters increase the number of possible configurations that affect the characteristics of the supply of power to the wheels. According to the traction characteristics of the car, the indicators of the traction and speed properties of the car are determined: the ability to overcome climbs, maximum acceleration, maximum speed on a horizontal road, acceleration time to a given speed, etc. The last two indicators depend primarily on the maximum power of ice or motor and are important for supercars, while for conventional cars or electric vehicles with close values of maximum speed and acceleration time to a given speed, they mean nothing. The authors propose to evaluate the efficiency of the drive during acceleration with maximum acceleration of the power utilization factor kN 0–100 – the particles from the division of the average value of the realized power on the wheels in the interval of speeds (0; 100) km/h by the maximum power value on the wheels. The characteristics of ICE and motors are given, traction characteristics in power coordinates are calculated – the speed of movement of cars with typical drive configurations, their power utilization coefficients are determined and appropriate conclusions are made. In the future, it is planned to investigate the use of power in more complex drive systems of hybrid cars with the recovery of braking energy.